I’ve reached the ‘frustrating’ part of the build. Getting the printer to behave dependably.
In improving the Z-stage alignment (alas, removing the @igus_Inc bushings for linear bearings), the z-stage now moves smoothly with relationship to Gravity.
I start with Z-max at the bottom, but airflow for the electronics cooling keeps the bed from reaching temp. (I need to shroud the electronics bay, but that’s coming.)
I set the G-code to lift the bed away from Z-Max, then heat the bed and nozzle
The stepper Drivers timeout before everything’s up to temp, meaning the bed now drifts away from the nozzle…making for a failed print.
I can’t find any references in Marlin to set the stepper timeouts.
(and yeah, I still haven’t worked out where to mount the Z-min endstop…one thing at a time.)
Wow quite a list… for no2 check the current you are allowing for the bed and increase it. If I recall its a % of 255 in marlin. called #define MAX_BED_POWER kine is set to 205 with a silicon head bed dont. Youbwant this as low as you can while getting your heatbed to warm quite quickly. Id imagine too much will fry your ramps
It’s not so much a list as the variables keeping the printer from “insert as card, press print” dependability.
I loaded PLA and turned off the heated bed and it did a convincing impression of a printer. but I still would have to preface “how to print” instructions with “make sure the nozzle is front left, make sure the bed is fully down”
I think the bed temp issue is one of total available current…I’m stuck with 12v on a relay for now.
// M84 - Disable steppers until next move, // or use S to specify an inactivity timeout, after which the steppers will be disabled. S0 to disable the timeout.
What was the reason for you to move away from igus bushings?
I was using their drop in replacements for 19mm OD 10mm ID bearings for the Z-stage and just comparing them side-by side with conventional linear bearings, there was more lateral play, and more drag than the equivalent VXB.
I hadn’t planned on replacing them. Assuming things are properly lubricated. (Alas, not something I needed to worry about with igus) I can’t imagine the loads would wear on the ceramic.
@Mike_Miller you could run the bed on a DC/DC SSR and run the bed power at 24v. I think that would double the power output. You would need to add a second power supply.
Otherwise convert the ramps to 24v using the same bed? This also has the advantage if driving the steppers better in my experiance. But now fans, etc need to be replaced along with poly fuses and other mods.
I am no electrical expert. I hope someone more knowledgeable than me can chime in.
It rapidly devolves into the point of diminishing returns. The bed CAN get to 100C, it just takes 10 minutes to do so. And if I’m honest, if I turnd the printer on, then requested it to pre-heat…it’s rare that I’m ready to print before it is.
120V kinda spooks me, though…now you’re talking real power that can cause harm if not handled correctly.
12V or 24V at the currents we’re handling is much more likely to cause harm (fires) than 120V at much lower currents. Yes, it does tingle a bit if you touch it, but i think properly isolating wires is much easier than designing everything for high current the right way. Plus, mains power is usually much better fused and protected (protected earth) than a diy low-voltage supply rail.
But your experiences with igus are being duplicated. I’m toying with machining my carriage out of aluminum, rather than printing it. We’ll see which way I go.
but I still would have to preface “how to print” instructions with “make sure the nozzle is front left, make sure the bed is fully down”